Liquid crystal display device

ABSTRACT

Without housing a bare chip type liquid crystal driver within a package, to surely shield or absorb the light which reaches the liquid crystal driver so that erroneous display due to the photoelectric effect can be prevented. A light shielding tape  109  is affixed to the top surface of an upper panel  101  of a liquid crystal display panel  10  at an area which is opposite to the mounting area of a liquid crystal driver  107  mounted on the bottom surface of the upper panel  101 . The light shielding tape  109  serves to shield the outer light incident on the liquid crystal driver  107 . A diffusion sheet  40  composed of a light diffusing area  401  and a light absorbing area  402  located on the outer periphery thereof is arranged below the liquid display panel  10 . The light diffusing area  401  serves to diffuse illumination light from a light source  202  to the liquid crystal display panel  10 , and the light absorbing area  402  serves to absorb the extraneous light incident on the liquid crystal driver  107.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a division of application Ser. No. 09/082,158filed on May 20, 1998 now U.S. Pat. No. 6,304,736.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display devicepackaged or mounted on a variety of electric appliances such as aportable telephone terminal, and more particularly to a liquid crystaldisplay device capable of assuring lightproofing of a bare-chip typeliquid crystal driver.

2. Description of the Related Art

Conventionally, in a liquid crystal display device to be mounted in avariety of electric appliances, a bare chip constituting a liquidcrystal driver therefor is housed in a package so that the lightreaching the bare chip is shielded.

With recent progress of low-profiling and down-sizing of a variety ofelectric appliances, a system of mounting or packaging the liquidcrystal driver has been shifted from surface mounting, in which a chipis completely light-shielded by a molding material, to COB (Chip onBoard), TCP (Tape Carrier package) and COG (Chip on Glass). In thesesystems, in which a bare chip of the liquid crystal driver is-mounted ona circuit board, the bare chip is susceptible to influence by light.

However, in the liquid crystal display device as described above, inwhich display is generally made by reflection of light, the bare chipwhich is not housed in a package is susceptible to influence byreflected light for display. Then, because of the reflected light, theliquid crystal driver gives rise to photoelectric effects leading toerroneous display. In addition, mounting the bare chip in a packagehinders low-profiling and down-sizing of electric appliances.

SUMMARY OF THE INVENTION

The present invention intends to solve the above conventional problemand to provide a liquid crystal display device capable of surelyshielding or absorbing light to reach a liquid crystal driver to preventerroneous display due to the photoelectric effect of the liquid crystaldriver.

Especially the object of the present invention is to prevent erroneousdisplay due to the photoelectric effect of the liquid crystal driver ina very thin type of the liquid crystal display device.

In order to solve the above problem, the liquid crystal display devicecomprises a liquid crystal driver mounted on a bottom surface of anupper panel constituting a liquid crystal display panel and a lightshielding film affixed to a top surface of the upper panel at an areawhich is opposite to a mounting position of the liquid crystal driverand serves to shield extraneous light incident on the liquid crystaldriver.

In accordance with the present invention, without housing the bare chiptype liquid crystal driver within a package, the light which reaches theliquid crystal driver is surely shielded or absorbed so that erroneousdisplay due to the photoelectric effect can be prevented.

The first of the present invention is a liquid crystal display devicewhich comprises:

a liquid crystal panel constituted by a first plate disposed on adisplaying side, a second plate disposed on a reverse side of thedisplaying side, and liquid crystal cells held therebetween;

a liquid crystal driver electrically connected with the liquid crystalpanel through a circuit pattern;

a light shielding material disposed on the displaying side of saidliquid crystal driver so as to prevent an outer light from beingincident to said liquid crystal driver. The shielding film surelyshields the light to reach the liquid crystal driver.

Preferably the present invention further comprises a diffusion sheetlocated below the liquid crystal display panel and composed of a lightdiffusing area and a light absorbing area located on the outer peripherythereof, the light diffusing area serving to diffuse illumination lightfrom a light source to the liquid crystal display panel, and the lightabsorbing area serving to absorb the extraneous light incident on theliquid crystal driver. The light absorbing area of the diffusing sheetabsorbs the extraneous light incident on the liquid crystal driver sothat the light to reach the liquid crystal driver is surely shielded.

Preferably the present invention is characterized in that the lightwhich reflects from said diffusion sheet to reach the liquid crystaldriver is shielded by resin applied for protecting a transparentelectrode of the liquid crystal display panel. The resin shields thelight reflected by the diffusion sheet to reach the liquid crystaldriver.

Preferably the invention is characterized in that the light shieldingfilm, light absorbing area of the diffusion sheet and resin are coloredin black. This configuration improves the shielding effect of light toreach the liquid crystal driver.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the exploded main part of a liquidcrystal display device according to a first embodiment of the presentinvention.

FIG. 2 is a side view of the liquid crystal panel portion of the liquidcrystal display device according to the first embodiment of the presentinvention.

FIG. 3 is a side view of the entire configuration of the liquid crystaldisplay device according to the first embodiment of the presentinvention

FIG. 4 is a side view of the liquid crystal panel portion of the liquidcrystal display device according to the second embodiment of the presentinvention.

FIG. 5 is a side view of the liquid crystal panel portion of the liquidcrystal display device according to the third embodiment of the presentinvention.

FIG. 6 is a side view of the liquid crystal panel portion of the liquidcrystal display device according to the fourth embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiment 1

Now referring to FIGS. 1 to 3, an explanation will be given of a firstembodiment of the present invention. FIG. 1 is a perspective view of theexploded main part of a liquid crystal display device according to thefirst embodiment of the present invention. FIG. 2 is a side view of theliquid crystal panel portion of the liquid crystal display deviceaccording to the embodiment of the present invention. FIG. 3 is a sideview of the entire configuration of the liquid crystal display deviceaccording to the embodiment of the present invention.

The liquid crystal display device to be mounted in a portable telephoneterminal, as seen from FIGS. 1 to 3, includes a liquid display panel 10,a circuit board 20 and a holder 30 for holding the liquid crystaldisplay panel 10 on the circuit board 20.

The liquid display panel 10, as apparent from FIG. 2, includes an upperpanel 101 as a first plate, a lower panel 102 as a second plate, anupper polarized plate 103 stacked on the upper surface of the upperpanel 101, a lower polarized plate 104 stacked on the lower surface ofthe lower panel 102, a reflection plate 105 affixed to the lower surfaceof the lower polarized plate and having a certain reflectivity andpermittivity, a first transparent electrode 106A arranged on the bottomsurface of the upper panel 101 opposite to the lower panel 102, a secondtransparent electrode 106B arranged on a upper surface of the lowerpanel 102, liquid crystal cell 100 sandwiched between the upper andlower panel 101, 102 and a liquid crystal driver 107 electricallyconnected to the first transparent electrode 106A. 100 s is a sealportion. The one end of a film carrier 108 is connected to the upperpanel 101 opposite to a mounting area of the liquid crystal driver 107,whereas the other end of the film carrier 108 is folded back to thebottom surface of the liquid crystal panel 10. The folding-back terminalis connected to a connector 201 mounted on the circuit board 20. And thefilm carrier 108 is consist of a resin film and circuit pattern formedon the resin film, and also act as a heat seal. A light shielding film109 is affixed to the upper surface of the upper panel 101 opposite tothe mounting area of the liquid crystal driver 107 and a connectingportion of the film carrier 108. The light shielding film 109 is coloredin black in order to enhance the light shielding effect. Silicon resinas a light shielding resin 110 is applied to the bottom surface of theupper panel 101 in order protect the first transparent electrode 106.The silicon resin 110 is colored in black in order to enhance the lightshielding effect of the liquid crystal driver 107.

A diffusion sheet 40 is affixed to the top surface of the holder whichis opposite to the bottom surface of the liquid crystal display panel. Alight diffusion area 401 of the diffusion sheet, opposite to thereflection plate 105 of the liquid display panel 10, is colored in whiteas shown in FIG. 1. A light absorption area 402, which is located at theouter periphery of the light diffusion area 401 and opposite to thebottom surface of the upper panel, is colored in black.

Four light sources 202 each being an LED are mounted oppositely to bothsides of the holder 30 so that the light radiated by the light sources202 are diffused with no luminance variation by the light diffusion area401 of the diffusion sheet 40 and the liquid crystal display panel 10 isilluminated from its bottom side.

Additionally, in FIG. 3, reference numeral 50 denotes a housing panel ofan electric appliance such as a portable telephone terminal, andreference 501 denotes a transparent housing cover which covers a displaywindow made on the housing panel oppositely to the upper polarized plateof the liquid display panel 10.

Now referring to FIG. 3, an explanation will be given of the operationof the embodiment configured as described above. The liquid displaydevice according to the embodiment adopts a semi-translucent displaysystem as a light gathering system in which the reflection plate 105having a certain reflectivity and permeability is arranged on the bottomsurface of the lower polarized plate 104 so that at a bright site,incident light rays (outer light rays) A and B are used (reflectiontype) whereas in a dark side, the light sources are lit up (transparenttype).

The operation where the extraneous light rays A and B are used fordisplay is as follows. The light ray A having certain energy, which isincident through the housing cover 501, is to enter the liquid crystaldriver 107 from the upper panel 101. The light ray A, however, isshielded by the light shielding film 109 so that it does not reach theliquid crystal driver 107. A part of the incident light ray B havingcertain energy is reflected by the diffusion sheet 40. The reflectedlight reaches the liquid crystal driver 107, but is shielded by thesilicon resin 110. A part of the incident light ray B is also absorbedby the light absorption area 402 of the diffusion sheet 40 so that itdoes not reach the liquid crystal driver 107.

Thus, in accordance with this embodiment, the light ray to directlyreach the liquid crystal driver is shielded by the light shielding tape109, and the light ray which reaches the liquid crystal driver and isreflected therefrom can be partially absorbed by the diffusion sheet 40.Therefore, without housing the bare chip type liquid crystal driverwithin a package, the light which reaches the liquid crystal driver issurely shielded or absorbed so erroneous display due to thephotoelectric effect can be prevented.

Embodiment 2

Now referring to FIG. 4, an explanation will be given of a secondembodiment of the present invention. FIG. 4 is a side view of the liquidcrystal panel portion of TCP type of the liquid crystal display deviceaccording to the second embodiment of the present invention.

In the second embodiment, a liquid crystal driver 107 is mounted on adisplaying side surface on a extended part of a lower panel 102, andelectrically connected to the first transparent electrode 106A. And thestructure is characterized in that a displaying side surface of theliquid crystal driver 107 is covered with a light shielding resin and alight shielding tape is affixed on the reverse side of the extended partof the lower panel corresponding to opposite region to a mounting areaof the liquid crystal driver 107.

Another parts are constructed in a same manner as the first embodiment,same members are numbered same as the first embodiment.

According to the second embodiment, both surface of the a bare chip ofthe liquid crystal driver 107 are covered with a light shielding resin110 and light shielding tape 107, thereby the light which reaches theliquid crystal driver 107 is surely shielded or absorbed so that theerroneous display due to the photoelectric effect can be prevented.

Embodiment 3

Now referring to FIG. 5, an explanation will be given of a thirdembodiment of the present invention. FIG. 5 is a side view of the liquidcrystal panel portion of TCP type of the liquid crystal display deviceaccording to the third embodiment of the present invention.

In the third embodiment, a liquid crystal driver 107 is mounted on adisplaying side surface of the folded portion of a film carrier 108folded under the display panel 10, and electrically connected to thecircuit pattern on the film carrier in a face down manner. In FIG. 5,same members are numbered same as the first embodiment. And thestructure is characterized in that a both surface of a bare chip of theliquid crystal driver 107 are covered with a light shielding resin 110and a light shielding tape 109, respectively.

Another parts are constructed same as the first embodiment, same membersare numbered same as the first embodiment.

According to the third embodiment, the liquid crystal driver 107 isdisposed under the display panel 10 and both surface of the a bare chipof the liquid crystal driver 107 are covered with a light shieldingresin 110 and light shielding tape 109, thereby the light which reachesthe liquid crystal driver 107 is surely shielded or absorbed so that theerroneous display due to the photoelectric effect can be prevented.

Embodiment 4

Now referring to FIG. 6, an explanation will be given of a fourthembodiment of the present invention.

FIG. 6 is a side view of the liquid crystal panel portion of TCP type ofthe liquid crystal display device according to the third embodiment ofthe present invention.

In the fourth embodiment, a liquid crystal driver 107 is mounted on adisplaying side surface of the folded portion of a film carrier 108folded under the display panel 10, like as the third embodiment. A chipof the liquid crystal display device is electrically connected to thecircuit pattern on the film carrier in a face up manner. In FIG. 6, samemembers are numbered same as the first embodiment. And the structure ischaracterized in that a displaying side surface of a bare chip of theliquid crystal driver 107 is covered with a light shielding resin 110and a light shielding tape 109.

Another parts are constructed same as the first embodiment, same membersare numbered same as the first embodiment.

And the present invention is applicable to resin shield type of a chipas well as bare chip type of a liquid crystal driver. In the case thatresin shield type of the chip is a thin type, the resin is not able toprevent a incident light to the chip sufficiently. But according to thepresent invention, the incident light to the chip is shieldedsufficiently.

As described above, without housing the bare chip type liquid crystaldriver within a package, the light which reaches the liquid crystaldriver is surely shielded or absorbed so that the erroneous display dueto the photoelectric effect can be prevented.

What is claimed is:
 1. A liquid crystal display device comprising: aliquid crystal panel comprising liquid crystal cells, a first platedisposed on a displaying side of the cells, and a second plate disposedon a reverse side of the cells; a liquid crystal driver electricallyconnected with the liquid crystal panel through a circuit pattern; and alight shielding material disposed adjacent said liquid crystal driver soas to prevent an outer light from being incident to said liquid crystaldriver; a film carrier comprising said circuit pattern formed on a resinfilm, wherein said liquid crystal driver is mounted on the liquidcrystal panel by a light shielding resin disposed on said liquid crystalpanel so as to cover one end of the film carrier and a side surface ofsaid liquid crystal driver.
 2. The liquid crystal display deviceaccording to claim 1, wherein one end of said liquid crystal panel islocated on the film carrier and said end is covered with a lightshielding film extending from said liquid crystal panel to said filmcarrier.
 3. The liquid crystal display device according to the claim 1,wherein said first plate has a reverse side facing the liquid crystalcells and an opposite displaying side said liquid crystal driver ismounted on the reverse side of the first plate, and said light shieldingmaterial comprises a light shielding film affixed to the displaying sideof said first plate so as to cover an area which is opposite to amounting position of said liquid crystal driver.
 4. The liquid crystaldevice according to claim 1, wherein said second plat has a displayingside facing the liquid crystal cells and an opposite revers side andsaid liquid crystal driver is mounted on the display side of the secondplate, and said light shielding material comprised a light shieldingfilm affixed to the reverse side of the second plate.
 5. The liquidcrystal display device according to claim 1, wherein the circuit patternis formed on a film carrier; said liquid crystal driver is mounted onthe film carrier and disposed under the second plate; and said lightshielding material comprises a light shielding film affixed to a surfaceof said liquid crystal driver facing the second plate.
 6. The liquidcrystal displaying device according to claim 5, wherein said liquidcrystal driver is mounted on a surface of said folm carrier facing thesecond plate; and a surface of said liquid crystal driver opposite thesecond plate is covered with light shielding resin.
 7. The liquidcrystal diplay device according to claim 6, wherein said liquid crystaldriver is mounted on a surface of said film carrier opposite the secondplate; and a surface of said lquid crystal driver facing the secondplate is covered with light shielding resin.
 8. The liquid crystaldisplay device according to the claim 1, wherein the device is furthermounted in a portable telephone terminal.
 9. A liquid crystal displaydevice comprising: a liquid crystal panel comprising liquid crystalcells, a first plate disposed on a displaying side of the cells, and asecond plate disposed on a reverse side of the cells; a liquid crystaldriver electrically connected with the liquid crystal panel through acircuit pattern; a light shielding material disposed adjacent saidliquid crystal driver so as to prevent an outer light from beingincident to said liquid crystal driver; and a diffusion sheet locatedadjacent said liquid crystal display panel, wherein said diffusion sheetis composed of a light diffusing area and a light absorbing area locatedon the outer periphery thereof, the light diffusing area serving todiffuse illumination light from a light source to the liquid crystaldisplay panel, and the light absorbing area serving to absorb theextraneous light incident on said liquid crystal driver; wherein saidliquid crystal driver is mounted on the liquid crystal panel by a lightshielding resin disposed on said liquid crystal panel so as to cover oneend of a film carrier and a side surface of said liquid crystal driver.10. The liquid crystal display device according to the claim 9, whereinthe first plate has a first transparent electrode, the second plate hasa second transparent electrode, and the liquid crystal cells are carriedbetween the first and second transparent electrodes and; the devicefurther comprises a light shielding resin covering an exposed area ofthe first transparent electrode from the liquid crystal cells so thatthe light which reflects from said diffusion sheet to reach the liquidcrystal is shielded.
 11. The liquid crystal display device according tothe claim 10, wherein said light shielding resin and said lightabsorbing area of said diffusion sheet are colored in black.
 12. Theliquid crystal display device according to the claim 10, wherein saidlight shielding resin is colored black.